What is a cryogenic liquid?

A cryogen or cryogenic liquid is defined by the National Institute for Standards and Technology (NIST) as any liquid with a boiling point below 93K (-180°C or -240°F) at 1 atmosphere of pressure. This definition includes liquid nitrogen (LN2), liquid argon (LAr), liquid helium (LHe), liquid hydrogen (LH2), and liquid oxygen (LO2), among others.

How does cryogen work?

Cryogen will inflict debuffs that hinder movement speed, such as Chilled and Glacial State. It will transition through six phases based on its current health, the final phase often being considered the most difficult, with Cryogen ramming the player at very high speeds. Cryogen is summoned by using a Cryo Key in the Snow biome at any time.

Is cryogen a hardmode boss?

Cryogen is a Hardmode boss that can be fought in the Snow or Ice biomes. Cryogen possesses many phases that it transitions to as its health decreases, and features a multitude of projectiles and enemies that it uses against the player. Defeating Cryogen will free the Archmage, as well as generate Cryonic Ore in the Ice biome.

Does cryogen spawn on its own?

Cryogen does not spawn on its own and requires the player to summon it with a Cryo Key while in the Snow biome or Ice biome at any time. Cryogen is additionally able to be summoned by killing 20 Primal Aspids . Cryogen has six phases, each of which has its own attack pattern and AI. It will progress through these phases as it loses health.